Background: Exosomes, key mediators of intercellular communication, transport functional biomolecules, making them promising tools for diagnostics and therapeutics across various human diseases. Objectives: To systematically review and analyze the clinical applications of exosomes, focusing on their sources, functions, therapeutic roles, and research trends through a bibliometric approach. Methodology: A comprehensive PubMed search was conducted using the term “exosomes” in titles and abstracts, limited to clinical studies, including Clinical Trials, Phase I–IV studies, and Randomized Controlled Trials. Ninety clinical trials were included. Bibliometric analysis using VOSviewer identified key terms, conceptual clusters, and emerging research topics. Results: Exosomes demonstrated diverse clinical applications in oncology, neurodegenerative diseases (e.g., Alzheimer’s), cardiovascular conditions, osteoarthritis, COVID-19, spinal cord injuries, transplant rejection, and skin regeneration. Predominant exosome sources included plasma, serum, urine, saliva, tears, ascites, adipose tissue, and stem cells. Functionally, exosomes served as diagnostic biomarkers, therapeutic agents, and molecular delivery systems. Key terms included miRNA, plasma, safety, efficacy, and trial, with conceptual clusters reflecting a shift from molecular exploration to clinical implementation. Emerging themes included precision medicine, biobank integration, and regenerative therapies using mesenchymal stem cell-derived or herbal-modified exosomes. Conclusion: Exosome-based interventions show promising safety and efficacy but face challenges in standardizing isolation methods, conducting large-scale randomized trials, and ensuring long-term follow-up. Future research should focus on integrating exosome platforms into precision medicine with robust clinical frameworks.